Leaching of heavy metals from chromated copper arsenate (CCA) treated wood after disposal

Wood treated by preservatives is commonly found in solid waste. Among the different types of preserved wood, chromated copper arsenate (CCA) treated wood recently has received much attention due to the scale of usage and its significant role in soil and water contamination. As the ash of CCA treated wood would be hazardous if the wood were to be incinerated, this is not a good alternative, and the best available disposal method is thus landfilling in the US, Canada and Australia. Leaching of the metals from preserved wood that is disposed in unlined landfills for construction debris pollutes the soil and water environments. Several factors affecting leaching of the metals from wood, including pH of the leachant, temperature, the duration of leaching and the type of leachant, were investigated. These factors affect each of the metals, chromium, copper and arsenic, differently. A comparison of these effects on each metal was performed. The results of the experiments showed that the pH of the leachants has a significant effect on the leaching process, and sulfuric acid (pH 3) is the most effective leachant compared to nitric and acetic acid (pH 3-4-5). The amounts of leached chromium, copper and arsenic by sulfuric acid (pH 3) during 15 days were, respectively, 0.2, 0.14 and 0.15 mg more than leachates by nitric acid (pH 5) on the basis of 1g of wood (initial contents of 1.03 mg, 0.42 g and 0.8 mg per g of wood). Most of the leaching occurs in the first 5 days, and the rate of leaching decreases significantly after 5 days. Increasing temperature increases the amount of leached metals, and arsenic is the least resistant metal to the leaching when the temperature increases. Increasing the temperature from 15 degrees C to 35 degrees C during 15 days increases the amount of leached chromium, copper and arsenic by acetic acid at pH 5 by about 0.1, 0.4 and 1.2mg per g of wood, respectively.     

Recycling plastics from automotive shredder residues: a review

Automotive shredder residue (ASR) is an inevitable by-product of car recycling, i.e. removal of all liquids and hazardous or valuable components from the car and shredding of the hulk, followed by the recovery of steel, iron, and non-ferrous scrap. The European Union (EU) ELV Directive requires attaining higher recovery and recycling rates, resulting in a reduction of the amount of ASR going to landfill. The most plausible methods to achieve a considerable reduction of ASR are as follows: either recycling of separated materials and dismantled bulky parts, such as bumpers, dashboards, cushions, and front and rear windows, or else systematic sorting of the commingled and size-reduced materials, resulting from shredding. After a brief comparison of the actual situation in the EU, the USA, and Japan, the characteristics of actual ASR are reviewed, as well as some of the most prominent efforts made to separate and recycle specific fractions, such as polyolefins, ABS, or polyurethane. Attention is paid to some major players in the EU and to some of the pitfalls that besiege these ventures.     

Analytical determination of the suitability of different processes for the treatment of odorous waste gas

In order to determine the efficiency of different treatment systems for the reduction of odorous emissions, a gas chromatographic method followed by simultaneous mass spectrometry and olfactometry (GC-MS/O) was developed. Samples from a coffee bean roasting and a fat and oil processing plant were analyzed, respectively. The results were compared with the data obtained by olfactometric measurements. At a coffee bean roasting plant, cooling gases were analyzed prior to and after treatment in a full scale bioscrubber. The GC-MS/O analysis showed that the amounts of aldehydes and ketones decreased after treatment of cooling gases of coffee bean roasting in the bioscrubber, whereas the contents of the heterocyclic compounds, like pyridine and the pyrazines, and acetophenone and guaiacol remained almost unchanged. The amounts of dimethyl disulfide, 3-hydroxy-2-butanone, and the carboxylic acids increased after bioscrubber treatment. Furthermore, the performance of each stage of a combined experimental plant for the treatment of exhaust air of fat and oil processing was investigated. This treatment plant consisted of a bioscrubber, a biofilter, and an activated carbon adsorber. The important odor-active compounds of the exhaust air of fat and oil processing were the typical fat oxidation products (aldehydes, ketones) and with lower importance 2-pentylfuran, a few terpenes and aromates. Again, the key odor-active compounds, aldehydes and ketones, were degraded in the bioscrubber. Further degradation of aliphatic, unsaturated, methylated, and cyclic alkanes, as well as aromates, terpenes, and furans by the biofilter was observed. After the last treatment stage, the activated carbon filter, only small amounts of aliphatic, unsaturated, methylated, and cyclic alkanes and aromates remained in the waste gas. For both applications, the results of the developed GC-MS/O method correlated very well with olfactometric measurements.     

Comparative management of offshore posidonia residues: composting vs. energy recovery

Residues of the marine plant posidonia (Posidonia oceanica, PO) beached in tourist zones represent a great environmental, economical, social and hygienic problem in the Mediterranean Basin, in general, and in the Apulia Region in particular, because of the great disturb to the bathers and population, and the high costs that the administrations have to bear for their removal and disposal.In the present paper, Authors determined the heating values of leaves and fibres of PO, the main offshore residues found on beaches, and, meantime, composted those residues with mowing and olive pruning wood. The final composts were characterized for pH, electrical conductivity, elemental composition, dynamic respiration index, phytotoxicity, fluorescence and infrared spectroscopic fingerprints.The aim of the paper was to investigate the composting and energy recovery of PO leaves and fibres in order to suggest alternative solutions to the landfill when offshore residues have to be removed from recreational beaches.The fibrous portion of PO residues showed heating values close to those of other biofuels, thus suggesting a possible utilization as source of energy.At the same time, compost obtained from both PO wastes showed high quality features on condition that the electrical conductivity and Na content are lowered by a correct management of wetting during the composting.     

Improvement and modification of the routing system for the health-care waste collection and transportation in Istanbul

Handling of health-care wastes is among the most important environmental problems in Turkey as it is in the whole world. Approximately 25–30 tons of health-care wastes, in addition to the domestic and recyclable wastes, are generated from hospitals, clinics and other small health-care institutions daily on the European and the Asian sides of İstanbul [Kocasoy, G., Topkaya, B., Zeren, B.A., Kılıç, M., et al., 2004. Integrated Health-care Waste Management in İstanbul, Final Report of the LIFE00 TCY/TR/054 Project, Turkish National Committee on Solid Wastes, İstanbul, Turkey; Zeren, B.A., 2004. The Health-care Waste Management of the Hospitals in the European Side of İstanbul, M.S. Thesis, Boğaziçi University, İstanbul, Turkey; Kılıç, M., 2004. Determination of the Health-care Waste Handling and Final Disposal of the Infected Waste of Hospital-Medical Centers in the Anatolian Side of İstanbul. M.S. Thesis, Boğaziçi University, İstanbul, Turkey]. Unfortunately, these wastes are not handled, collected or temporarily stored at the institutions properly according to the published Turkish Medical Waste Control Regulation [Ministry of Environment and Forestry, 2005. Medical Waste Control Regulation. Official Gazette No. 25883, Ankara, Turkey]. Besides the inappropriate handling at the institutions, there is no systematic program for the transportation of the health-care wastes to the final disposal sites. The transportation of these wastes is realized by the vehicles of the municipalities in an uncontrolled, very primitive way. As a consequence, these improperly managed health-care wastes cause many risks to the public health and people who handle them.This study has been conducted to develop a health-care waste collection and transportation system for the city of İstanbul, Turkey. Within the scope of the study, the collection of health-care wastes from the temporary storage rooms of the health-care institutions, transportation of these wastes to the final disposal areas and the cost-benefit analyses of the existing and the proposed optimum transportation routes are investigated and the most feasible routes from the point of view of efficiency and economy have been determined.In order to solve the scheduling and route optimization problem, special software programs called MapInfo and Roadnet were used. For the program, the geocodes of hospital locations, data about the amount of the health-care wastes generated, the loading and unloading process times, and the capacity of the collecting vehicles were taken into account. The new systems developed aim at the daily collection of the health-care wastes from the institutions and their transportation directly to the final disposal area/facility by using the shortest and the most efficient routes to resolve the routing and scheduling problem and to reduce the cost arising from the transportation.     

A historical context of municipal solid waste management in the United States.

Municipal solid waste management (MSWM) in the United States is a system comprised of regulatory, administrative, market, technology, and social subcomponents, and can only be understood in the context of its historical evolution. American cities lacked organized public works for street cleaning, refuse collection, water treatment, and human waste removal until the early 1800s. Recurrent epidemics forced efforts to improve public health and the environment. The belief in anticontagionism led to the construction of water treatment and sewerage works during the nineteenth century, by sanitary engineers working for regional public health authorities. This infrastructure was capital intensive and required regional institutions to finance and administer it. By the time attention turned to solid waste management in the 1880s, funding was not available for a regional infrastructure. Thus, solid waste management was established as a local responsibility, centred on nearby municipal dumps. George Waring of New York City organized solid waste management around engineering unit operations; including street sweeping, refuse collection, transportation, resource recovery and disposal. This approach was adopted nationwide, and was managed by City Departments of Sanitation. Innovations such as the introduction of trucks, motorized street sweepers, incineration, and sanitary landfill were developed in the following decades. The Resource Conservation and Recovery Act of 1976 (RCRA), is the defining legislation for MSWM practice in America today. It forced the closure of open dumps nationwide, and required regional planning for MSWM. The closure of municipal dumps caused a 'garbage crisis' in the late 1980s and early 1990s. Private companies assumed an expanded role in MSWM through regional facilities that required the transportation of MSW across state lines. These transboundary movements of MSW created the issue of flow control, in which the US Supreme Court affirmed the protection of garbage under the Commerce Clause of the Constitution. Thus MSWM in America today is largely managed by municipalities, and operated by a relatively small number of private companies. It consists of a mixture of landfill, incineration, recycling, and composting, and is regulated under RCRA, the Clean Air Act and other related federal and state laws.     

Selecting state-of-the-art incinerators for complex aqueous wastes

The Rocky Mountain Arsenal (RMA) in Adams County, Colorado has been identified as a priority site on the Superfund National Priority List. The Program Manager's Office of RMA announced in early 1990 its intention to implement installation of a state-of-the-art incineration plant to treat the most complex and controversial waste stream on the site. Established in 1942, RMA served as an Army manufacturing center for chemical agents such as mustard gas, white phosphorus, napalm, and GB nerve agent. Parts of the site were also leased to Shell Oil Company, which manufactured pesticides and other agricultural chemicals at this location between 1952 and 1982. To support these activities, the Army operated a ninety-three-acre surface impoundment called Basin F for collection and evaporation of chemical wastewaters. As a result of the wide variety of wastes received and concentrated at Basin F and early treatment attempts, its contents became one of the most unusual chemical cocktails known to man. By the time a formal interim response action for remediation was initiated in 1985, the composition of the Basin consisted of a multi-phase fluid and sludge, including super-saturated levels of inorganic salts; 30 percent or more organics such as pesticides, military agent by-products, degradation products, and solvents; high levels of ammonia compounds and bound nitrogen; and percent levels of copper, arsenic, and other metals. Selection of a remedial alternative involved twelve years of characterizationstudies and eleven years of treatability testing programs encompassing the universe of containment; encapsulation; stabilization; component separation; and thermal, electrical, chemical, and biological degradation technologies. The program resulted in the selection of a state-of-the-art down-fired liquid incinerator for destruction of aqueous organic contaminants in metallic salt matrices. The treatability demonstration, and the technical justification for selection of the T-Thermal submerged quench incinerator for this application, is the subject of this article.     

典型磷矿区表层土壤重金属空间分布特征研究

以开阳磷矿区为对象,结合地统计学普通克里金插值法以及单因素分析法,研究了矿区表层土壤重金属的空间分布特征,并对其进行了污染评价。结果表明：以矿区当地土壤重金属背景值为标准,Cu,Zn,Pb,Cd,As含量均存在超标情况;5种元素含量的变异程度均为高度变异,Pb,Cd,As的变异系数远大于Cu,Zn的变异系数;土壤重金属空间分布特征为Cd,As含量在东北部的积累程度大于西南部,东北—东南方向Cu,Zn,Pb,Cd,As的富集程度远大于西北—西南方向;不同土地利用类型对重金属的积累没有显著影响,这很可能与其他因素如背景值、风向、人类干扰（如化工产业）等有关。     

Integrated Environmental and Hydraulic Design of Xerias River,Corinthos, Greece,Training Works

The modern design of flood protection and training works in cases of major natural streams and creeks, requires a fine balance between a sound engineering approach in all engineering aspects on one hand, and an environmentally acceptable solution on the other. Progress in integrating environmental and hydraulic design has been achieved over the years due to different factors, like proper collaboration of engineering disciplines, hydraulic modeling enhancement, development and use of suitable materials, amelioration of the construction methods, and proper restoration and use of the affected areas. In this paper, a synopsis of the experience that has been gained by our firm over the years in designing flood protection and river training works for urban and rural areas is presented, including the general design principles to be used as guidelines, and illustrated with the case study of river Xerias, Greece. The river Xerias is located in Peloponnese, Greece. It flows from south to north and has a catchment area of 170 km². For the last 1500 m before discharging into the Corinthian gulf, the river flows through the city of Corinthos. This is the reach, which overflowed and flooded the city during the January 1997 flood, causing a lot of damage and human life casualties.     

Soil bioassays as tools for sludge compost quality assessment

Composting is a waste management technology that is becoming more widespread as a response to the increasing production of sewage sludge and the pressure for its reuse in soil. In this study, different bioassays (plant germination, earthworm survival, biomass and reproduction, and collembolan survival and reproduction) were assessed for their usefulness in the compost quality assessment.Compost samples, from two different composting plants, were taken along the composting process, which were characterized and submitted to bioassays (plant germination and collembolan and earthworm performance). Results from our study indicate that the noxious effects of some of the compost samples observed in bioassays are related to the low organic matter stability of composts and the enhanced release of decomposition endproducts, with the exception of earthworms, which are favored. Plant germination and collembolan reproduction inhibition was generally associated with uncomposted sludge, while earthworm total biomass and reproduction were enhanced by these materials. On the other hand, earthworm and collembolan survival were unaffected by the degree of composting of the wastes. However, this pattern was clear in one of the composting procedures assessed, but less in the other, where the release of decomposition endproducts was lower due to its higher stability, indicating the sensitivity and usefulness of bioassays for the quality assessment of composts.     

Impacts of natural weathering on the transformation/neoformation processes in landfilled MSWI bottom ash: a geoenvironmental perspective

Natural weathering processes are significant mechanisms that noticeably affect the fundamental nature of incineration ash residues. To provide a greater understanding of these processes, a MSWI (mono)landfill site in the north east of the US was selected as the target for systematic investigation of the natural weathering of bottom ash residues. Samples of various ages were collected from locations A (1 yr), B (10 yrs), C (13-14 yrs) and D (20 yrs) of the landfill in 2009. We investigated the phase transformation of the collected bottom ash particles, neoformation processes as well as the behavior and distribution of certain heavy metals (Cu, Pb, Zn, Ni, and Cr) in the neoformed phases using optical microscopy, SEM-EDX, and bulk examinations. Key findings: at the preliminary stage, the waste metallic particles (Al, Fe, and Cu) and unstable minerals such as lime, portlandite, ettringite and hydrocalumite convert to oxide and hydroxide (hydrate) phases, calcite, alumina gel and gypsum. At the intermediate stage, the decomposition of melt products including magnetite spinels and metallic inclusions is triggered due to the partial dissolution of the melt glass. At the longer time horizon it is possible to track the breakdown of the glass phase, the extensive formation of calcite and anhydrite, Al-hydrates and more stable Fe-hydrates all through the older ash deposits. Among the dominant secondary phases, we propose the following order based on their direct metal uptake capacity: Fe-hydrates>Al-hydrates>calcite. Calcite was found to be the least effective phase for the direct sorption of heavy metals. Based on overall findings, a model is proposed that demonstrates the general trend of ash weathering in the landfill.     

Influence of TiO<Subscript>2</Subscript> Nanoparticles on the Crystallization Behaviour and Tensile Properties of Biodegradable PLA and PCL Nanocomposites

This paper investigated the influence of TiO₂ nanoparticles on the morphologies, as well as crystallization behaviour and kinetics, of neat PLA and PCL, and of these polymers in different PLA/PCL blends. We used transmission electron microscopy to evaluate the morphologies of the systems, while the crystallization behaviour and kinetics were investigated through differential scanning calorimetry (DSC). In addition to standard and modulated (StepScan) DSC analyses, the self-nucleation temperatures of neat PCL and PCL in the different nanocomposites were determined, followed by a self-nucleation and annealing thermal fractionation analysis of PCL crystallization and an Avrami isothermal kinetic analysis of PCL crystallization and PLA cold crystallization. We found that the nanoparticles were well dispersed, but only in the PLA phase of the blends, with only a few on the interface or in the PCL phase. They did nucleate and accelerate, and influence the mechanism of, the PCL crystallization in neat PCL, but had little influence on PCL crystallization in the blends. They strongly influenced the rate of cold crystallization of PLA, but had little influence on this parameter in the blends. The tensile properties were also determined, and changes in these properties could be related to the morphologies of the systems.     

Integrated solid waste management based on the 3R approach

Integrated solid waste management (ISWM) based on the 3R approach (reduce, reuse, and recycle) is aimed at optimizing the management of solid waste from all the waste-generating sectors (municipal, construction and demolition, industrial, urban agriculture, and healthcare facilities) and involving all the stakeholders (waste generators, service providers, regulators, government, and community/neighborhoods). This article discusses the concept of solid waste management (SWM). Initially, SWM was aimed at reducing the risks to public health, and later the environmental aspect also became an important focus of SWM. Recently, another dimension is becoming a critical factor for SWM, i.e., resource conservation and resource recovery. Hence, the 3R approach is becoming a guiding factor for SWM. On the one hand, 3R helps to minimize the amount of waste from generation to disposal, thus managing the waste more effectively and minimizing the public health and environmental risks associated with it. On the other hand, resource recovery is maximized at all stages of SWM. Lately, the new concept of ISWM has been introduced to streamline all the stages of waste management, i.e., source separation, collection and transportation, transfer stations and material recovery, treatment and resource recovery, and final disposal. It was originally targeted at municipal solid waste management (MSWM), but now the United Nations Environment Programme (UNEP) is promoting this concept to cover all waste generating sectors to optimize the level of material and resource recovery for recycling as well as to improve the efficiency of waste management services. The ISWM concept is being transformed into ISWM systems to replace conventional SWM systems. This article further discusses the implementation process for ISWM. The process includes a baseline study on the characterization and quantification of waste for all waste generating sectors within a city, assessment of current waste management systems and practices, target setting for ISWM, identification of issues of concern and suggestions from stakeholders, development of a draft ISWM plan, preparation of an implementation strategy, and establishment of a monitoring and feedback system. UNEP is assisting member countries and their cities to develop an ISWM plan covering all the waste generating sectors within a specific geographical or administrative area such as a city or municipality. This umbrella approach is useful to generate sufficient volumes of recycling materials required to make recycling industries feasible. This is also helpful for efficient reallocation of resources for SWM such as collection vehicles, transfer stations, treatment plants, and disposal sites. UNEP is assisting cities to develop and implement ISWM based on the 3R approach. These experiences could be useful for other countries to develop and implement ISWM to achieve improved public health, better environmental protection, and resource conservation and resource recovery.     

建筑可持续发展视角下供应链协调与社会责任共担机理研究方案架构

基于建筑全生命周期这个主线,建筑可持续发展视角下供应链协调与社会责任共担机理研究,以绿色建筑供应链运行效率为导向,以既有建筑节能改造效率为切入点,以产业链过程中各主体行为规律为基础,采用“总-分-合”的基本研究思路模式,聚焦了“主导企业驱动下绿色建筑供应链协调机理与策略、既有建筑节能改造主体社会责任共担机理、建筑废弃物再生利用产业链主体社会责任共担机理”等三部分核心内容,初步形成建筑可持续发展视角下供应链协调与社会责任共担机理的理论体系。本成果采用“总-分-合”的思路模式,基于循环经济理念和主体行为策略视角,遵循研究的学理逻辑,以研究生学位论文为基础,开展“主导企业驱动下绿色建筑供应链协调机理与策略、既有建筑节能改造主体社会责任共担机理、建筑废弃物再生利用产业链主体社会责任共担机理”3个子课题研究,从系统整体概况实施全面研究规划着手,构架了总括、绿色建筑供应链协调机理、既有建筑节能改造主体社会责任共担、建筑废弃物再生利用社会责任共担、总结等五大模块及上中下三大篇共12章的系统体系。     

解读《关于深入推进重点行业清洁生产审核工作的通知》

2020年10月16日,生态环境部和国家发改委联合发布了《关于深入推进重点行业清洁生产审核工作的通知》（环办科财〔2020〕27号）（《通知》）,以进一步加强清洁生产审核在重点行业节能减排和升级改造中的支撑作用,促进形成绿色发展方式,推动经济高质量发展。本文在分析《通知》出台的背景和意义的基础上,对清洁生产审核工作的顶层设计、模式创新、奖惩措施等方面进行梳理和解读,助力各地方深入理解《通知》精神,推动各项任务有效落实。     

Predicting the mobility of Zn, Fe, Cu, Pb, Cd from roasted sulfide (pyrite) residues—A case study of wastes from the sulfuric acid industry in Sweden

Leachates from roasted sulfide residues, which are the wastes from the production of sulfuric acid at Falun, Sweden, have low pH and high concentrations of Zn, Fe, and SO₄. The minerals are mainly hematite and maghemite and, because the various sulfides in the feed behave differently during the roasting process, the residual sulfides minerals are pyrrhotite and sphalerite. Oxidation of the residual sulfides contributes acidity, Zn, Fe, Cu, Cd, and sulfate to the effluents from the waste deposits. The dissolution of sphalerite is most likely accelerated in acid solution rich in Fe (III). The formation of Pb-sulfate coatings on galena may provides an armoring effect which slows the oxidation of the galena. Residual sulfides are source phases controlling long-term contaminant release. Other source minerals for Zn, Fe, Pb, Cu, Cd and SO₄ in the effluents are iron oxides which retained percentage quantities of SO₄, roast-derived alteration rims of Zn oxides on sphalerite, alterated silicates formed during the roasting process, and secondary minerals (e.g. Zn, Fe, Cu sulfates, iron hydroxides) that were precipitated by in-site oxidation in the waste dumps. The Zn, Fe, and Cu sulfates most likely control short-term changes in the chemistry of the leachate, while Pb concentration in the leachates may be controlled predominantly by Pb-release from the altered silicates. The mineralogical and geochemical data provide fundamental information essential for the remedial management of this type of industial waste.     

Characterization of municipal solid waste from the main landfills of Havana city

The city of Havana, the political, administrative and cultural centre of Cuba, is also the centre of many of the economic activities of the nation: industries, services, scientific research and tourism. All of these activities contribute to the generation of municipal solid waste (MSW), which also impact other Cuban cities. Inadequate handling of waste and the lack of appropriate and efficient solutions for its final disposal and treatment increase the risk and possibility of contamination. The main difficulty in the development of a system of management of MSW lies in the lack of knowledge of the chemical composition of the waste that is generated in the country as a whole, and especially in Havana, where solid waste management decisions are made. The present study characterizes MSW in Havana city during 2004. The Calle 100, Guanabacoa and Ocho Vías landfills were selected for physical-chemical characterization of MSW, as they are the three biggest landfills in the city. A total of 16 indicators were measured, and weather conditions were recorded. As a result, the necessary information regarding the physical-chemical composition of the MSW became available for the first time in Cuba. The information is essential for making decisions regarding the management of waste and constitutes a valuable contribution to the Study on Integrated Management Plan of MSW in Havana.     

协同创新视角下资环专业研究生科技创新能力提升途径

资源循环科学与工程专业硕士毕业生存在规模小、科技创新能力不足、能力施展受限等问题,无法满足产业对高层次人才的需求。究其原因有:(1)新兴专业,其研究生导师队伍建设不健全,人才培养质量参差不齐;(2)交叉专业,其科技创新能力培养方向尚需融合凝练;(3)综合专业,其现有科研平台还不足以支撑学科发展,科技创新能力培养模式还没有完全形成。因此,本学科研究生培养单位应树立协同创新理念,坚持行业需求导向,充分挖掘办学特色和优势,凝练培养方向、完善以科技创新能力培养核心的研究生培养方案;加强师资队伍建设,建立健全科研平台;支持鼓励科技创新实践活动,做好学科前沿追踪;加强校校交流互动,提升硕士点认可度。     

燃煤锅炉脱砷现状研究

通过对国内外燃煤锅炉脱砷现状的研究，探讨各种脱砷方法的优、缺点，提出锅炉脱砷的可行方案。把砷污染的产生与锅炉运行实际结合起来考虑，脱砷过程可以分为燃烧前、燃烧中、燃烧后三段。燃烧前脱砷对于无机砷可以达到70％以上的效率，而对有机砷则会产生富集作用；燃烧中脱砷可利用现有的脱硫技术和设备，如炉内喷钙技术和循环流化床锅炉，其脱除效率分别达到40％、80％；燃烧后脱砷方法主要包括提高除尘器效率法、化学法、吸收剂法，这些方法基本都能使除砷效率理论值达到90％以上，具有极佳的工业应用前景。